1. Field of the Invention
The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus for automatically controlling the image forming conditions according to the exposure and development characteristics of the recording medium.
2. Description of Related Art
An image forming apparatus for forming an image on a developer member, in which pressure development is executed by overlapping and subjecting the exposed photosensitive medium and the developer member to pressure is known. The photosensitive recording medium used in such an image forming apparatus has various photosensitivity and development characteristics as a result of the manufacturing process and the material used. As a result, the optimum conditions for exposing and developing the copied image are different for each photosensitive recording medium and the user must input the specified optimum conditions to the image forming apparatus prior to starting the image forming process. However, in the known image forming apparatus discussed above, the user must manually input the information associated with exposure and developing conditions. Therefore, there are problems in that the operation is very complex, requiring special controls, and an input mistake can prevent formation of an optimum image.
An image forming apparatus has been proposed in GB2211631A to solve such problems. According to the disclosed image forming apparatus, an information mark, such as a bar code, providing the exposure and developing conditions for the photosensitive medium are formed on a leading portion of the photosensitive recording medium. The information mark is read in the image forming apparatus and the image forming conditions are automatically set according to the information.
According to such an image forming apparatus, the information mark, such as the bar code, formed on the leading portion of the photosensitive recording medium is read during the automatic feeding of the recording medium. However, when the photosensitive recording medium is fed automatically, the leading portion of the photosensitive recording medium has an inherently unstable leading free edge. Because of this, it was necessary for the reading device to have a guiding mechanism to reduce the instability of the leading edge of the sheet containing the information mark. Still, reading focus is sufficiently unstable that the reading errors may result.